Kodak trendsetter vlf laser safety loop error!


Hey folks,

Any help would be great here.

We have a Kodak Trendsetter VLF, and we have an intermittent message as bellow:

"Head i/f: mbx==NULL, defauting to unsolicited
MPE -> Host: [ U 2 17699 14 0 Exposure Head: Laser safety loop has just opened ]"

Whenever this error happens I can not record. I have already checked that the security doors are open and if ani interlock is open, but everything is ok. When the error happens or i wait the safety loop to close or i can close whit the command "laser test".

It may be coincidence, but when i turn off the chiller, the error does not happen, and when the temperature reaches the limit, not to abort the recording i turn it on again, and after a while the error starts to happen randomly. I think it´s something connected to temperature, Brasil´s technician here said it might be some bug in MPE software.

Folks, i need a lot of help, because I´ve had this problem for years and nobody has been able to figure out the problem. I´ve alread take the head and put it on another machine an it worked without problem.

Thanks for any help.

Last edited:


Active member
We have a Trendsetter News that once kept telling us the Safety Switch was engaged and we needed to rotate it 90 degrees. trust me when I say, the safety switch was thoroughly not engaged. We checked with the company that performs service for us and he suggested thumping the relays on the board in the electronics end. I don't know how the layout of the VLF differs from the News but on the news, you pretty much have all the electronics in one end. One of the boards has a number or mechanical relays and apparently one of them was sticking. I think we use either our finger nails or maybe an ink pen and tapped on all the relays. Sure enough, that fixed the problem. I'm not saying this is the answer to your problem but it worked for us.
Primarily safety loop protects machine operator from IR radiation and mechanical hazards. Every operator associates it with open panels. But safety loop also protects the machine from working in inadequate conditions. Safety loop is sophisticated subroutine based on number of sensors and acting in the real time during production.

We can help you fix the problem. Please send me pm or contact at your convenience.

Les Zmyslowski


Apresys, Inc.
3650 N. Cicero Ave.
Chicago, IL 60641

TEL:(773)545-7700 Toll Free:(800)899-8111 USA Fax:(773)685-9229

Web Site: http://www.viprofix.com E-mail: lzmyslowski@viprofix.com


Thanks for the tip ssutton503, unfortunately I did the procedure but it did not work. I think it has something to do with temperature, because when I turn off the chiller, the problem happens less frequently. Thank you for your help.


Well-known member
The error message "Exposure Head: Laser safety loop has just opened" on your CtP Trendsetter VLF has to do with your laser head. More specifically, it is related to the power in the laser head. My company will confirm the reason for this error message by remotely accessing your Trendsetter. We will solve this problem.
If you are further interested, please send me an email to pwarzecha@viprofix.com

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